An image sensing device is a device for capturing at least one image using photosensitive characteristics semiconductor that react to light. In recent times, with the increasing development of computer industries and communication industries, demand for high-quality and high-performance image sensors is rapidly increasing in various fields, for example, digital cameras, camcorders, personal communication systems (PCSs), game consoles, surveillance cameras, medical micro-cameras, robots, etc.
Image sensing devices may be broadly classified into CCD (Charge Coupled Device)-based image sensing devices and CMOS (Complementary Metal Oxide Semiconductor)-based image sensing devices. Recently, since an analog control circuit and a digital control circuit can be directly implemented as a single integrated circuit (IC), CMOS-based image sensing devices have rapidly come into widespread use.